1. Field of the Invention
The present invention relates generally to antenna technology for an electronic device, and more particularly, to antenna technology using a case of an electronic device.
2. Background of the Invention
As transmission and processing speeds of electronic devices used for wireless communication increase, devices such as smart phones, which provide a user assistance function in addition to a web surfing function, have become mainstream in wireless communication.
An electronic device typically includes an antenna for performing wireless communication. This antenna has developed into a built-in antenna device in order to enhance the portability of the electronic device.
A code division multiple access (CDMA), global system for mobile communication (GSM), or wideband CDMA (WCDMA) communication technique typically use three to four frequency bands. For example, an antenna installed in most WCDMA terminals only needs to support a frequency band of 2100 MHz (a WCDMA antenna needs to support a frequency band of 850 MHz/1900 MHz in North America). Also, in accordance with a long term evolution (LTE) technique, it is possible to use various frequency bands depending on a country or region for wireless communication.
Since an electronic device provides many functions, the types and numbers of chips and sensors installed in the electronic device has increased, and thus, the space in which an antenna may be mounted has decreased. Also, since an LTE service is provided at a plurality of bands, and thus, an antenna device that covers various frequency bands should be provided, a number of structurally different antennas may be required for wireless communication.
The electronic device may include an antenna for supporting Bluetooth (BT), Wi-Fi, global positioning system (GPS), near field communication (NFC), and infra-red data association (IrDA) communication, and an antenna for supporting digital multimedia broadcasting (DMB).
When the electronic device includes various types of antennas, various problems may result, such as, for example, lack of antenna mounting spaces, constraint on the design of the electronic device, and excessive heat emission. Also, mounting an antenna for a service that is used only in specific countries or an antenna for a communication frequency band that is not used outside specific countries causes inefficiency in productivity.